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Doc: improve Mandelbrot example

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Change-Id: Iac6c3e681f3d5b195d08513ac5fe4b661c3d0f59
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
This commit is contained in:
Mitch Curtis 2018-09-10 10:51:33 +02:00
parent 621ab8ab59
commit e04b85b026
1 changed files with 8 additions and 8 deletions
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16
examples/corelib/threads/doc/src/mandelbrot.qdoc
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@ -39,7 +39,7 @@
The heavy computation here is the Mandelbrot set, probably the The heavy computation here is the Mandelbrot set, probably the
world's most famous fractal. These days, while sophisticated world's most famous fractal. These days, while sophisticated
programs such as \l{http://xaos.sourceforge.net/}{XaoS} that provide real-time zooming in the programs such as \l{http://matek.hu/xaos/doku.php}{XaoS} that provide real-time zooming in the
Mandelbrot set, the standard Mandelbrot algorithm is just slow Mandelbrot set, the standard Mandelbrot algorithm is just slow
enough for our purposes. enough for our purposes.
@ -201,7 +201,7 @@
\snippet threads/mandelbrot/renderthread.cpp 9 \snippet threads/mandelbrot/renderthread.cpp 9
Once we're done with all the iterations, we call Once we're done with all the iterations, we call
QWaitCondition::wait() to put the thread to sleep by calling, QWaitCondition::wait() to put the thread to sleep,
unless \c restart is \c true. There's no use in keeping a worker unless \c restart is \c true. There's no use in keeping a worker
thread looping indefinitely while there's nothing to do. thread looping indefinitely while there's nothing to do.
@ -232,7 +232,7 @@
\snippet threads/mandelbrot/mandelbrotwidget.cpp 0 \snippet threads/mandelbrot/mandelbrotwidget.cpp 0
The implementation starts with a few contants that we'll need The implementation starts with a few constants that we'll need
later on. later on.
\snippet threads/mandelbrot/mandelbrotwidget.cpp 1 \snippet threads/mandelbrot/mandelbrotwidget.cpp 1
@ -256,15 +256,15 @@
slot later on. Qt knows how to take of copy of many C++ and Qt slot later on. Qt knows how to take of copy of many C++ and Qt
types, but QImage isn't one of them. We must therefore call the types, but QImage isn't one of them. We must therefore call the
template function qRegisterMetaType() before we can use QImage template function qRegisterMetaType() before we can use QImage
as parameter in queued connections. as a parameter in queued connections.
\snippet threads/mandelbrot/mandelbrotwidget.cpp 2 \snippet threads/mandelbrot/mandelbrotwidget.cpp 2
\snippet threads/mandelbrot/mandelbrotwidget.cpp 3 \snippet threads/mandelbrot/mandelbrotwidget.cpp 3
\snippet threads/mandelbrot/mandelbrotwidget.cpp 4 \snippet threads/mandelbrot/mandelbrotwidget.cpp 4
In \l{QWidget::paintEvent()}{paintEvent()}, we start by filling In \l{QWidget::paintEvent()}{paintEvent()}, we start by filling
the background with black. If we have nothing yet to paint (\c the background with black. If we have nothing to paint yet (\c
pixmap is null), we print a message on the widget asking the user pixmap is null), we display a message on the widget asking the user
to be patient and return from the function immediately. to be patient and return from the function immediately.
\snippet threads/mandelbrot/mandelbrotwidget.cpp 5 \snippet threads/mandelbrot/mandelbrotwidget.cpp 5
@ -293,7 +293,7 @@
Notice that we rely on \c resizeEvent() being automatically Notice that we rely on \c resizeEvent() being automatically
called by Qt when the widget is shown the first time to generate called by Qt when the widget is shown the first time to generate
the image the very first time. the initial image.
\snippet threads/mandelbrot/mandelbrotwidget.cpp 11 \snippet threads/mandelbrot/mandelbrotwidget.cpp 11
@ -307,7 +307,7 @@
control the zoom level. QWheelEvent::delta() returns the angle of control the zoom level. QWheelEvent::delta() returns the angle of
the wheel mouse movement, in eights of a degree. For most mice, the wheel mouse movement, in eights of a degree. For most mice,
one wheel step corresponds to 15 degrees. We find out how many one wheel step corresponds to 15 degrees. We find out how many
mouse steps we have and determine the zoom factor in consequence. mouse steps we have and determine the resulting zoom factor.
For example, if we have two wheel steps in the positive direction For example, if we have two wheel steps in the positive direction
(i.e., +30 degrees), the zoom factor becomes \c ZoomInFactor (i.e., +30 degrees), the zoom factor becomes \c ZoomInFactor
to the second power, i.e. 0.8 * 0.8 = 0.64. to the second power, i.e. 0.8 * 0.8 = 0.64.